Fastify, a fast and low overhead web framework for Node.js, is actively improving its type definitions to provide a better developer experience for Node.js TypeScript developers. The later TypeScript v3 releases and the new v4 updates have provided many great patterns and practices for Fastify's types. In Fastify's latest major release (v3) they shipped an overhauled type definition set that utilized advanced patterns such as discriminant unions and function overloading, named generic parameters, generic inference, and declaration merging. Today's talk by Fastify maintainer, Ethan Arrowood, will give an overview of how they utilized these patterns, plans for the new TypeScript v4.1 template literal types, and more.
Ethan Arrowood is a maintainer for Fastify, and an active open source contributor to Node.js. He is currently employed as a Software Engineer by Microsoft based out of Cambridge, Massachusetts. When he is not working, he can most likely be found hiking, skiing, or camping somewhere in the Northeast US.